Polymerization of methyl acrylate initiated by V(V)-cyclohexanone redox system in micellar phase

Abstract

ABSTRACT:The kinetics of methyl acrylate (MA) polymerization initiated by a V(V)-Cyclohexanone redox system, in the presence of surfactant, over a temperature range of 30-50ЊC in acidic medium are analyzed. The anionic surfactant (SDS) enhances the rate of polymerization ( R p ) as well as the rate of V(V) consumption ( 0R v ). The cationic surfactant, cetyl trimethylammonium bromide (CTAB), decreases both the rates. The effect of variation of the concentration of surfactant, monomer, substrate, and acid have been examined. A suitable free radical mechanistic scheme has been proposed for the above process.

Polymerization of Acrylamideinitiated by V(v)-Cyclohexanone Redox System in Micellar Phase: A Kinetic Study

“…But, in the presence of cationic surfactant, the rates as well as the percentage of acrylamide conversion decreased considerably as compared to that in absence of surfactant. The rate of consumption of V(V), -R V was found to increase with the SDS concentration and decrease with an increase of CTAB as observed in our earlier work [19,20]. SDS also increased the rate of acrylamide polymerization using peroxodiphosphate as initiator [27].…”

“…Under our experimental conditions, the termination is more effective than the initiation, which leads to a decline in the rate at a higher concentration of V(V) [19,20]. V(V) has the capability of influencing both the initiation and the termination processes.…”

“…At a higher concentration of cyclohexanone, its solubilization in the micellar part will be more, leading to a greater number of free radicals [14][15][16][17][18][19][20][21] which enhances the rate. This can be explained on the basis of solubilization.…”

Acrylonitrile polymerization initiated by Ce(IV)–cyclohexanone redox system in presence of surfactant

“…The filtrate, along with washings after separation of the polymer, was estimated for residual Ce(IV) by cerimetry using feroin as an indicator. The rate of polymerization and the rate of Ce(IV) consumption were calculated from the initial slope of the curve of the percentage of monomer conversion versus time and Ce(IV) consumption versus the time curve, respectively 16, 17, 20…”

“…A review of the literature reveals that surfactants have been used in vinyl polymerization initiated by various redox systems in different forms, for example, emulsions,1–9 microemulsions,10–15 micelles,16–18 and adsolubilaztion 19. Some work has been done on the effect of a surfactant on polymerization processes using Ce(IV) as an initiator 20.…”